The present invention relates to a feed mechanism for use in connection with document handling machinery but specifically adapted for the purpose of separating documents, sheets, coupons and the like. More specifically, the present invention relates to such a mechanism which is capable of separating documents from one another so that they may be fed individually one at a time to a subsequent mechanism and which is self-adjusting to accept documents of different thicknesses.
In the prior art various types of feed mechanisms for separating documents and feeding those documents from a stack individually through further mechanisms have been devised. The prior art document selection mechanisms have been adjustable devices which have to be carefully adjusted for selected document thicknesses and which are subject to malfunction if thicknesses vary substantially from document to document. They have had to be relatively complicated structures in order to permit thickness selection. In some cases, their complication has made them or caused them to become difficult to adjust. Their adjustments and some of the rest of the mechanisms may be subject to getting out of adjustment or becoming permanently inoperable, particularly in circumstances where they may be roughly handled, as during shipment. Certain ranges of documents, particularly relatively thin documents such as tissues, are extremely hard to handle by any prior art device. Furthermore, it is difficult to assure that under some circumstances adjacent documents will not stick together and be passed through the rest of the mechanism and erroneously identified as a single document, leading to data errors as well as simple miscounts of documents.